Structure and Function of Arteries, Capillaries and Veins Flashcards
Name the blood vessels that carry
blood away from the heart
Arteries
What do capillaries do
allow exchange of materials between the
blood and tissues
Name the blood vessels that carry
blood back in to the heart
veins
Describe the pathway of blood
through vessels from the heart back
to the heart
Arteries > Capillaries > Veins
Describe the change in the blood
pressure as it moves away from the
heart
increases
Name the channel in each blood
vessel and state the name of the
tissue which lines this
Lumen
lined with endothelial cells
Describe the composition of
arteries, beginning with the lumen
moving outwards
Endothelial lining
thick middle layer of muscle and elastic fibres
outer layer of connective tissue
elastic fibres
Why do the elastic walls of the
arteries stretch and recoil?
To accommodate the surge of blood
after each contraction of the heart
Term used when smooth muscle in
arteries contract
Vasoconstriction
The term used when smooth muscle
in arteries relax
Vasodilation
Explain the purpose of
vasoconstriction and vasodilation
Allows for blood flow to be
controlled
Which feature of a capillary allows
exchange of substances with tissues?
Thin walls
Describe the composition of veins,
beginning from the lumen working
outwards
Endothelial lining,
thin middle layer of muscle
outer layer of connective tissue and elastic fibres
State the purpose of valves in vein
Prevent backflow of blood
The process which causes plasma to
pass through capillary walls into
Tissues
Pressure filtration
Give examples of substances which
diffuse from tissue fluid into cells
Glucose, oxygen, amino acids, other
small molecular molecules
Give examples of substances that
diffuse out of cells into tissue fluid
and then return to the blood
CO2 and waste
What happens to most of the
tissue fluid?
It returns to the blood
What happens to excess tissue
fluid?
Absorbed by lymphatic vessels and
returned as lymph to the circulatory
system
State how tissue fluid and blood
plasma differ in composition
plasma proteins are too large to be filtered
through capillary walls so aren’t found in tissue fluid
